The burden of vestibular disorders among military health system (MHS) beneficiaries, fiscal years 2018-2019.

INTRODUCTION: Vestibular disorders affect an estimated 33 million adults and 3.5 million children and adolescents in the United States. Previous research relying on self-reported symptoms versus actual diagnosis has limited the ability to provide prevalence estimates for specific vestibular disorders at the population level. This study seeks to describe the burden of vestibular disorders among children and working-age adult beneficiaries in the Military Health System (MHS). MATERIALS AND METHODS: Using the MHS Data Repository (MDR), we conducted a cross-sectional study of all TRICARE Prime and Plus MHS beneficiaries aged 0 to 64 years from fiscal years (FY) 2018 to 2019. Study analyses included descriptive statistics of patient demographics and assessing the prevalence of vestibular disorders in pediatric and working-age adult beneficiaries. RESULTS: Of the 5,541,932 TRICARE Prime/Prime Plus MHS beneficiaries, 52,878 (0.95%) had a diagnosis of vestibular disorder during fiscal years 2018 to 2019, of which 1,359 were pediatric and adolescents (aged 0 to 17 years) and 51,519 were working-age adults (18 to 64 years). Vertigo was the most common diagnosis in both age-group populations (11.46 per 1,000 working-age adults; 0.52 per 1,000 children and adolescents), with benign vertigo being the most prevalent of the three diagnoses and occurring at a seven times higher rate in adults versus pediatric and adolescents. CONCLUSIONS: This study demonstrates the effectiveness of using medical claims data to estimate prevalence compared to self-reported survey data and supports prevalence estimates of vestibular disease in <1% of children overall, but indicate much higher prevalence for adolescents.

Categorizing individuals based on the severity of Visual Vertigo Analogue Scale symptoms.

BACKGROUND: The Visual Vertigo Analogue Scale (VVAS) assesses visual vertigo. Instead of the original scoring methods (positive VVAS > 1), we propose categorizing patients as having No (0), Mild (0.1-40), Moderate (40.01-70), or Severe (70.01-100) symptoms. OBJECTIVE: Our primary aim was to validate an alternative interpretation of the VVAS by exploring the relationship between categories of visual vertigo symptoms and measures of activity and participation, dizziness handicap, anxiety, and depression. We aimed to describe the severity of visual vertigo reported by patients in different vestibular diagnostic categories. METHODS: Participants with vestibular disorders (n = 250) completed the VVAS, Vestibular Activities and Participation (VAP) Measure, Dizziness Handicap Inventory (DHI), and the Hospital Anxiety and Depression Scale (HADS). RESULTS: Patients with central disorders were more symptomatic than those with peripheral vestibular disorders. As evaluated by one-way ANOVA, the scores on the VAP, HADS, and DHI significantly differed among mild, moderate, severe, and no visual vertigo categories (p < 0.001). As VVAS severity increased, activity and participation decreased (r = 0.582, p < 0.001); dizziness handicap increased (r = 0.597, p < 0.001, n = 199); anxiety increased (r = 0.405, p < 0.001); and depression increased (r = 0.521, p < 0.001). CONCLUSIONS: The findings of this study support the use of an alternative VVAS interpretation method of categorizing symptoms as none, mild, moderate, and severe visual vertigo.

A systematic review of longitudinal risk factors for loneliness in older adults.

OBJECTIVES: To effectively reduce loneliness in older adults, interventions should be based on firm evidence regarding risk factors for loneliness in that population. This systematic review aimed to identify, appraise and synthesise longitudinal studies of risk factors for loneliness in older adults. METHODS: Searches were performed in June 2018 in PsycINFO, Scopus, Sociology Collection and Web of Science. Inclusion criteria were: population of older adults (M = 60+ years at outcome); longitudinal design; study conducted in an OECD country; article published in English in a peer-review journal. Article relevance and quality assessments were made by at least two independent reviewers. RESULTS: The search found 967 unique articles, of which 34 met relevance and quality criteria. The Netherlands and the United States together contributed 19 articles; 17 analysed national samples while 7 studies provided the data for 19 articles. One of two validated scales was used to measure loneliness in 24 articles, although 10 used a single item. A total of 120 unique risk factors for loneliness were examined. Risk factors with relatively consistent associations with loneliness were: not being married/partnered and partner loss; a limited social network; a low level of social activity; poor self-perceived health; and depression/depressed mood and an increase in depression. CONCLUSION: Despite the range of factors examined in the reviewed articles, strong evidence for a longitudinal association with loneliness was found for relatively few, while there were surprising omissions from the factors investigated. Future research should explore longitudinal risk factors for emotional and social loneliness.

The Shelterin TIN2 Subunit Mediates Recruitment of Telomerase to Telomeres.

Dyskeratosis Congenita (DC) is a heritable multi-system disorder caused by abnormally short telomeres. Clinically diagnosed by the mucocutaneous symptoms, DC patients are at high risk for bone marrow failure, pulmonary fibrosis, and multiple types of cancers. We have recapitulated the most common DC-causing mutation in the shelterin component TIN2 by introducing a TIN2-R282H mutation into cultured telomerase-positive human cells via a knock-in approach. The resulting heterozygous TIN2-R282H mutation does not perturb occupancy of other shelterin components on telomeres, result in activation of telomeric DNA damage signaling or exhibit other characteristics indicative of a telomere deprotection defect. Using a novel assay that monitors the frequency and extension rate of telomerase activity at individual telomeres, we show instead that telomerase elongates telomeres at a reduced frequency in TIN2-R282H heterozygous cells; this recruitment defect is further corroborated by examining the effect of this mutation on telomerase-telomere co-localization. These observations suggest a direct role for TIN2 in mediating telomere length through telomerase, separable from its role in telomere protection.

Tissue-specific apoptotic effects of the p53 codon 72 polymorphism in a mouse model.

Currently there are several dozen human polymorphisms that have been loosely associated with cancer risk. Correlating such variants with cancer risk has been challenging, primarily due to factors such as genetic heterogeneity, contributions of diet and environmental factors, and the difficulty in obtaining large sample sizes for analysis. Such difficulties can be circumvented with the establishment of mouse models for human variants. Recently, several groups have modeled human cancer susceptibility polymorphisms in the mouse. Remarkably, in each case these mouse models have accurately reflected human phenotypes, and clarified the contribution of these variants to cancer risk. We recently reported on a mouse model for the codon 72 polymorphism in p53, and found that this polymorphism regulates the ability to cooperate with NF-kB and induce apoptosis. Here-in we present evidence that this polymorphism impacts the apoptotic function of p53 in a tissue-specific manner; such tissue-specific effects of polymorphic variants represent an added challenge to human cancer risk association studies. The data presented here support the premise that modeling human polymorphisms in the mouse represents a powerful tool to assess the impact of these variants on cancer risk, progression and therapy.

Regulation of female reproduction by p53 and its family members.

Tumor suppressor p53 is crucial for embryonic implantation through transcriptional up-regulation of uterine leukemia inhibitory factor (LIF). This article reports that p53 and estrogen receptor α were activated in endometrial tissues during implantation to coordinately regulate LIF production. By using human p53 knockin (Hupki) mice carrying a single nucleotide polymorphism (SNP) at codon 72 (arginine/proline), the arginine allele was demonstrated to produce higher uterine LIF levels during implantation than the proline allele. In humans, the diversity of haplotypes of the p53 gene has decreased during evolution, because the arginine allele, existing in only a subset of haplotypes, is under positive selection. This observation is consistent with previous results showing that the proline allele is enriched in patients undergoing in vitro fertilization (IVF). Studies with p63- and p73-knockout mice have demonstrated the involvement of p63 and p73 in female reproduction and their roles in egg formation and apoptosis (p63) and spindle checkpoint (p73) in female mice. Here, the role of p63 and p73 in human reproduction was investigated. Selected alleles of SNPs in p63 and p73 genes were enriched in IVF patients. These findings demonstrate that the p53 family members are involved in several steps to regulate female reproduction in mice and humans.

Wild-type and mutant p53 proteins interact with mitochondrial caspase-3.

Caspases play a key role in the apoptotic pathway by virtue of their ability to cleave key protein substrates within the dying cell. Caspases are produced as inactive zymogens, and need to become proteolytically processed in order to become active. A key executioner caspase, caspase-3, has previously been found to exist in both the cytosol and the mitochondria. At the mitochondria, caspase-3 is associated with both the inner and outer mitochondrial membranes, where it interacts with heat shock proteins Hsp60 and Hsp10. Like caspase-3, a small portion of the p53 tumor suppressor protein is localized to mitochondria, particularly after genotoxic stress. p53 interacts with various members of the Bcl2 family at the mitochondria, and this interaction is key to its ability to induce apoptosis. In this study, we sought to determine the identity of other mitochondrial p53-interacting proteins. Using immunoprecipitation from purified mitochondria followed by mass spectrometry we identified caspase-3 as a mitochondrial p53-interacting protein. Interestingly, we find that tumor-derived mutant forms of p53 retain the ability to interact with mitochondrial caspase-3. Further, we find evidence that these mutant forms of p53 may interfere with the ability of procaspase-3 to become proteolytically activated by caspase-9. The combined data suggest that tumor-derived mutants of p53 may be selected for in tumor cells due to their ability to bind and inhibit the activation of caspase-3.

The codon 72 polymorphism of p53 regulates interaction with NF-{kappa}B and transactivation of genes involved in immunity and inflammation.

A common polymorphism at codon 72 in the p53 tumor suppressor gene encodes either proline (P72) or arginine (R72). Several groups have reported that in cultured cells, this polymorphism influences p53's transcriptional, senescence, and apoptotic functions. However, the impact of this polymorphism within the context of a living organism is poorly understood. We generated knock-in mice with the P72 and R72 variants and analyzed the tissues of these mice for apoptosis and transcription. In the thymus, we find that the P72 variant induces increased apoptosis following ionizing radiation, along with increased transactivation of a subset of p53 target genes, which includes murine Caspase 4 (also called Caspase 11), which we show is a direct p53 target gene. Interestingly, the majority of genes in this subset have roles in inflammation, and their promoters contain NF-κB binding sites. We show that caspase 4/11 requires both p53 and NF-κB for full induction after DNA damage and that the P72 variant shows increased interaction with p65 RelA, a subunit of NF-κB. Consistent with this, we show that P72 mice have a markedly enhanced response to inflammatory challenge compared to that of R72 mice. Our data indicate that the codon 72 polymorphism impacts p53's role in inflammation.

A dual-targeting PDGFRbeta/VEGF-A molecule assembled from stable antibody fragments demonstrates anti-angiogenic activity in vitro and in vivo.

Targeting angiogenesis is a promising approach to the treatment of solid tumors and age-related macular degeneration (AMD). Inhibition of vascularization has been validated by the successful marketing of monoclonal antibodies (mAbs) that target specific growth factors or their receptors, but there is considerable room for improvement in existing therapies. Combination of mAbs targeting both the VEGF and PDGF pathways has the potential to increase the efficacy of anti-angiogenic therapy without the accompanying toxicities of tyrosine kinase inhibitors and the inability to combine efficiently with traditional chemotherapeutics. However, development costs and regulatory issues have limited the use of combinatorial approaches for the generation of more efficacious treatments. The concept of mediating disease pathology by targeting two antigens with one therapeutic was proposed over two decades ago. While mAbs are particularly suitable candidates for a dual-targeting approach, engineering bispecificity into one molecule can be difficult due to issues with expression and stability, which play a significant role in manufacturability. Here, we address these issues upstream in the process of developing a bispecific antibody (bsAb). Single-chain antibody fragments (scFvs) targeting PDGFRbeta and VEGF-A were selected for superior stability. The scFvs were fused to both termini of human Fc to generate a bispecific, tetravalent molecule. The resulting molecule displays potent activity, binds both targets simultaneously, and is stable in serum. The assembly of a bsAb using stable monomeric units allowed development of an anti-PDGFRB/VEGF-A antibody capable of attenuating angiogenesis through two distinct pathways and represents an efficient method for rapid engineering of dual-targeting molecules.

Engineering of stable bispecific antibodies targeting IL-17A and IL-23.

Bispecific antibodies (bsAbs) present an attractive opportunity to combine the additive and potentially synergistic effects exhibited by combinations of monoclonal antibodies (mAbs). Current challenges for engineering bsAbs include retention of the binding affinity of the parent mAb or antibody fragment, the ability to bind both targets simultaneously, and matching valency with biology. Other factors to consider include structural stability and expression of the recombinant molecule, both of which may have significant impact on its development as a therapeutic. Here, we incorporate selection of stable, potent single-chain variable fragments (scFvs) early in the engineering process to assemble bsAbs for therapeutic applications targeting the cytokines IL-17A/A and IL-23. Stable scFvs directed against human cytokines IL-23p19 and IL-17A/A were isolated from a human Fab phage display library via batch conversion of panning output from Fabs to scFvs. This strategy integrated a step for shuffling V regions during the conversion and permitted the rescue of scFv molecules in both the V(H)V(L) and the V(L)V(H) orientations. Stable scFvs were identified and assembled into several bispecific formats as fusions to the Fc domain of human IgG1. The engineered bsAbs are potent neutralizers of the biological activity of both cytokines (IC(50) < 1 nM), demonstrate the ability to bind both target ligands simultaneously and display stability and productivity advantageous for successful manufacture of a therapeutic molecule. Pharmacokinetic analysis of the bsAbs in mice revealed serum half-lives similar to human mAbs. Assembly of bispecific molecules using stable antibody fragments offers an alternative to reformatting mAbs and minimizes subsequent structure-related and manufacturing concerns.